星载SAR姿态误差及偏航调整对多普勒特性的影响

分析了卫星姿态、天线斜视角、地球旋转、目标高度等因素对星载合成孔径雷达（ＳＡＲ）多普勒特性的影响，旨在研究测绘带上多普勒中心频率、多普勒调频斜率、零多普勒偏移、目标位置等星载ＳＡＲ处理参数．在各种因素的影响下回波信号多普勒频率可能会变得很高，给方位聚焦处理带来很大的困难．通过Ｃ－ＳＡＲ系统参数仿真计算了这些因素对多普勒特性的影响，证明了理论分析的正确性．

Effect of Spaceborne SAR Attitude Errors and Yaw Steering on the Doppler Characteristics

The effect of satellite attitude, antenna squint, earth rotation and target height on Doppler characteristics of spaceborne Synthetic Aperture Radar(SAR) is discussed with the goal to research spaceborne SAR processing parameters, such as Doppler center frequency, Doppler rate, zero Doppler shift and target position. The variations of Doppler frequency may be very high in some cases, which makes the azimuth focusing processing impossible. To resolve these problems, a method referred to as yaw steering is used to point antenna boresight in the direction of zero Doppler frequency and obtain the minimum Doppler frequency variation. The influences of these factors on the Doppler characteristics are calculated with C SAR system parameters, and results show the theoretical analysis is correct.